How do you unlock everything in the Gallery?

Somebody please help me. I have successfully completed this game 5 times and 3 times with an A-Rank, but I still can't figure out how to unlock the Gallery. If anybody can help me please e-mail me with this information.I would be ever so grateful. My e-mail is babyyy2527@aol.com Thanks so much

He is on the 2nd floor where there are 2 chest of drawers. I'm sure you were in that room a lot at the beginning of the game. Wait next to the middle chest and you'll see him get tired and then suck him up.

Do you know how to save at this point? I can't figure it out since the lights went out and Toad went missing.